Department of Animal Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
Receive Date: 24 April 2012,
Revise Date: 26 June 2012,
Accept Date: 06 July 2012
The main purpose of this study was to evaluate the influence of the photoperiod on the seminal traits of crossbreed wool-producing rams throughout on year period. For the effect of photoperiod two periods were considered: decreasing daylight length (summer and autumn) and increasing daylight length (winter and spring). For the study 5 Baluchi × Moghani (BL×MG) and 5 Arkharmerino × Moghani (AM×MG) rams were used. Semen collection started from first of October 2010 to end of September 2011. After a training period of 2 weeks semen ejaculates were evaluated for volume, total sperm count per ejaculate (TSE), spermatozoa concentration, semen color, wave motion, percentage of progressive motility, percentage of live and abnormal spermatozoa, semen pH, methylene blue reduction time (MBRT) and semen index (semen volume × spermatozoa concentration/mL × live spermatozoa % × progressive motility %).Analysis of the yearlong data showed that semen samples with the best quality were collected in September to November (P<0.05). Significant seasonal variations of semen traitswere observed for all of seminal traitsexcept for progressive motility, percentage of live spermatozoa and MBRT. Yet, nostatistical differences were found between the two genetic groups (P>0.05). Although there were significant seasonal changes in semen characteristics of the crosses, the fresh semen showed adequate quality to be used for artificial or natural insemination all around the year. Photoperiod was found to influence semen production in two genetic groups at 38 ˚02' N, 46 ˚27' E at an altitude of 1567 m above sea level of Iran. However, these effects should are not detrimental to the use of rams for breeding purposes throughout the year.
Al-Ghalban A.M., Tabbaa M.J. and Kridli R.T. (2004). Factors affecting semen characteristics and scrotal circumference in Damascus bucks. Small Rumin. Res.53, 141-149. Amir D., Gacitua H., Ron M. and Lehrer A.R. (1986). Seasonal variation in semen characteristics and the fertility of Finn cross rams subjected to frequent ejaculation. Anim. Reprod. Sci.10, 75-84. Aurich C., Burgmann F. and Hoppe H. (1996). Opioid regulation of LH and prolactin release in the horse identical or independent endocrine pathways? Anim. Reprod. Sci. 44, 127-134. Barkawi A.H., Elsayed E.H., Ashour G. and Shehata E. (2006). Seasonal changes in semen characteristics, hormonal profiles and testicular activity in Zaraibi goats. Small Rumin. Res.66, 209-213. Chandler J.E., Harrison C.M. and Canal A.M. (2000). Spermatozoal methylene blue reduction: an indicator of mitochondrial function and its correlation with motility. Theriogenology.54, 261-271. Chemineau P., Malpaux B., Delgadillo J.A., Guerin Y., Ravault J.P., Thimonier J. and Pelletier J. (1992). Control of sheep and goats reproduction: use of light and melatonin. Anim. Reprod. Sci.30, 157-184. Colas G., Lefebvre J. and Guerin J. (1990). Father-male offspring transmission of seasonal variations in testis diameter and percentage of abnormal sperm in the Ile-de-France rams: male offspring born in February. Reprod. Nutr. Dev.30, 589-603. Colas G., Lefebvre J. and Guerin J. (1988). Recherche d'une prevision precoce de l'amplitude des variations saisonnieres du diameter testiculaire et du pourcentage de spermatozoids anormaux chez le belier lle-de-France: 1. Animaux nes en fevrier. Reprod. Nutr. Dev. 28, 589-601. Dacheux J.L., Pisselet C., Blanc M.R., Hocherau de Reviers M.T. and Courot M. (1981). Seasonal variation in rat testis fluid secretion and sperm production in different breeds of rams.J. Reprod. Fertil.61, 363-71. Deldar Tajangookeh H., Zare shahneh A., Moradi shahrebabak M. and Shakeri M. (2007). Monthly variation of plasma concentration of testosterone and thyroid hormones and reproductive characteristics in three breeds of Iranian fat-tailed rams throughout one year. Pakistan J. Bio. Sci. 10, 3420-3424. Ernst L.K. and Dmitriev N.G. (2007). Sheep: transbalkan finewool.ftp: //ftp.fao.org /docrep/ fao/009/ ah759e/ah 759e16.pdf. Galal E.S.E., El-Gamal A.A. and Aboul-Naga A. (1978). Male reproductive characteristics of Merino and Ossimi sheep and their crosses. Anim. Prod.27, 261-267. Gerlach T. and Aurich J.E. (2000).Regulation of seasonal reproductive activity in the stallion, ram and hamster. Anim. Reprod. Sci.58, 197-213. Goot H. (1969). Effect of light on spring breeding of mutton Merino ewes. J. Agri. Sci. Cambridge. 73, 177-180. Gorman M.R. and Zucker I. (1995a). Seasonal adaptions of Siberian hamsters: II. Pattern of change in day length controls annual testicular and body weight rhythms. Biol. Reprod.53, 116-125. Gundogan M. (2007). Seasonal variation in serum testosterone, T3 and andrological parameters of two Turkish sheep breeds. Small Rumin. Res.67, 312-316. Hafez E.S.E. (1952). Studies on the breeding season and reproduction of the ewe. J. Agri. Sci. Cambridge.42, 189-265. Haynes N.B. and Schanbacher B.D. (1983). The control of reproductive activity in the ram. Pp. 431-451 in Sheep Production. Butterworths, London. Ibrahim S.A. (1997). Seasonal variations in semen quality of local and crossbred rams raised in the United Arab Emirates. Anim. Reprod. Sci. 49, 161-167. Janett F., Thun R., Niederer K., Burger D. and Hassig M. (2003). Seasonal changes in semen quality and freezability in the Warmblood stallion. Theriogenology.60, 453-461. Kafi M., Safdarian M. and Hashemi M. (2004). Seasonal variation in semen characteristics, scrotal circumference and libido of Persian Karakul rams. Small Rumin. Res. 53,133-139. Karagiannidis A., Varsakeli S., Alexopoulos C. and Amarantidis I. (2000). Seasonal variation in semen characteristics of Chios and Friesian rams in Greece. Small Rumin. Res.37,125-130. Karagiannidis A., Varsakeli S. and Karatzas G. (1999). Characteristics and seasonal variations in the semen of Alpine, Assnen and Damascus goat bucks born and raised in Greece. Theriogenology.53,1285-1293. Kishk W.H. (2008). Interrelationship between ram plasma testosterone level and some semen characteristics. Slovak J. Anim. Sci. 41, 67-71. Mandiki S.N.M., Deriscke G., Bister J.L. and Paquay R. (1998). Influence of season and age on sexual maturation parameters of Texel, Suffolk, and Ile-de- France rams. 1. Testicular size, semen quality and reproductive capacity. Small Rumin. Res.28, 67-79. Mohamed S.A. (1978). Studies on some reproductive characters of native sheep. Ph D Thesis. Cairo Univ. Egypt. Nowakowski P. and Cwikla A. (1994). Seasonal variation in testis size in Polish Merino rams and its relationship to reproductive performance in spring. Theriogenology. 42, 613-622. Robinson J.J. (1981). Photoperiodic and nutritional influences on the reproductive performance of ewes in accelerated lambing systems. Pp. 1-10 in Proc. 32nd Annu. Mtg., of the Europ. Asso. Anim. Prod. (EAAP), Zagreb, Croatia. Robinson J.E. and Karsch F.J. (1987). Photoperiodic history and a changing melatonin pattern can determine the neuroendocrine response of the ewe to daylength.J. Reprod. Fertil.80, 159-165. Rosa H.J.D. and Bryant M.J. (2003). Seasonality of reproduction in sheep. Small Rumin. Res.48, 155-171. Salisbury G.W., VanDemark N.L. and Lodge J.R. (1978). Physiology of Reproductive and Artificial Insemination of Cattle. 2nd. Ed. San Francisco, CA: WH Freeman and Company. SAS Institute. (1996). SAS®/STAT Software, Release 6.11. SAS Institute, Inc., Cary, NC. Simplicio A.A., Riera G.S., Nelson E.A. and Pant K.P. (1982). Seasonal variation in seminal and testicular characteristics of Brazilian Somali rams in the hot semi-arid climate of tropical northeast Brazil. J. Reprod. Fertil.66, 735-738. Talebi J., Souria M., Moghaddam A., Karimi I. and Mirmahmoodi M. (2009). Characteristics and seasonal variation in the semen of Markhoz bucks in western Iran. Small Rumin. Res.85, 18-22. Zamiri M.J. and Khodaei H.R. (2005). Seasonal thyroidal activity and reproductive characteristics of Iranian fat-tailed rams. Anim. Reprod. Sci.88, 245-255. Zamiri M.J., Khalili B., Jafaroghli M. and Farshad A. (2010). Seasonal variation in seminal parameters, testicular size and plasma testosterone concentration in Iranian Moghani rams. Small Rumin. Res.94, 132-136. Zarazaga L.A., Guzman J.L., Domınguez C., Perez M.C. and Prieto R. (2005). Effect of plane of nutrition on seasonality of reproduction in Spanish Payoya goats. Small Rumin. Res.87, 253-267.